Study of the Day: Blood Tests Can Accurately Diagnose Depression

New research shows that blood screenings can accurately spot multiple telltale biomarkers in patients with classic symptoms of depression.

PROBLEM: Depression has traditionally been diagnosed with a questionnaire that assesses patients' reported symptoms. This process varies greatly, however, since it relies heavily on the clinician's experience and resources.

METHODOLOGY: To test if an objective biological test could improve diagnosis accuracy, scientists recruited 36 adults with major depression and 43 healthy participants for a blood screening. They measured the levels of nine biomarkers associated with depressive symptoms, such as inflammation, the development and maintenance of neurons, and the interaction between brain structures involved with stress response and other key functions.

RESULTS: The blood test indicated the presence of depression in 33 of the 36 patients and registered false positives for eight of the 43 participants in the control group. The scientists validated these findings with a second trial where 31 of the 34 depressed patients were also successfully diagnosed.

CONCLUSION: Blood tests can detect depression.

CAVEAT: The scientists are planning on conducting larger-scale studies in clinical settings to fine-tune their test. For now, though, study co-author John Bilello hopes that "the biological basis of this test may provide patients with insight into their depression as a treatable disease rather than a source of self-doubt and stigma."

SOURCE: The full study, "Assessment of a Multi-Assay, Serum-Based Biological Diagnostic Test for Major Depressive disorder: a Pilot and Replication Study," is published in the journal Molecular Psychiatry.